Mariah Carey could be. Mary J. Blige might be. And if Mariah and Mary are, then why not Whitney? Diana Ross is doubtful, but there are always Lauryn Hill, Faith Evans, and even Missy Elliott. No, no way. We have to draw the line somewhere. Not everyone can be a diva. The word “diva,” which originally meant goddess in Latin, is quickly losing any such significance. These days, the media are quick to drop the title on any singing showboat who bares her tonsils to an audience. Under the circumstances, a concert called the “Honey Nut Cheerios Sisters Soulfest” could very likely be a disaster of adolescent wannabe divettes smiling for their cereal-box photos and singing their single hit songs. Picture the lineup: Brandy at the top of show, preceded by Mya or even—if we’re lucky—Britney Spears. And they could get that annoying little curly-headed girl from the Pepsi commercials to open. Fortunately, the General Mills people have opted for a nutritious, balanced concert featuring two bona fide divas: Patti LaBelle (pictured) and Chaka Khan. If there were a standardized test for divahood, Jennifer Lopez might score well on sex appeal, and Madonna would ace the drama section, but would either of them really measure up against LaBelle’s explosive stage presence or Khan’s expansive vocal range? Kick off your shoes and walk through the fire at 8 p.m. Friday, Aug. 27, at DAR Constitution Hall, 18th & D Streets NW. $60. (202) 628-4780. (Neil Drumming)